Summary:
Haemodiafiltration (HDF) is renal replacement therapy. It is a method of blood clearance based on the principle
of diffuse and convection transport of substances through a semipermeable membrane. The method uses high-flux
membranes, usually synthetic ones with a high ultrafiltration coefficient. According to the principle of preparation
of a substitution solution HDF is divided into bag methods (substitution solutions in bags), on-line HDF (continual
preparation of substitution solution in an apparatus in the course of the procedure) and HDF based on reversed
filtration of the dialyzation solution through the membrane of the haemodiafilter. Depending on the length and
frequency of the procedure, there is intermittent HDF used in particular in the treatment of chronic renal failure and
continual HDF used in acute conditions where renal failure is part of multiorgan dysfunction. Depending on the site
of administration of the substitution solution, we differentiate between predilution HDF (the substitution solution
is administered into the blood stream before haemodiafiltration) and postdilution HDF (the substitution solution is
administered into the bloodstream after the haemodiafilter). HDF methods are highly effective in the elimination of
low-molecular and medium-molecular substances. They are effective and well tolerated by patients. They can be
used under conditions when standard haemodialysis is associated with circulatory instability or is not sufficiently
effective. The author describes principles and possibilities of application of different modifications of HDF methods.
Key words:
renal replacement therapy, haemodiafiltration, chronic renal failure, solutions for haemodiafiltration,
indications for haemodiafiltration
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